Safety switch mechanism



Feb. 7, 1933. JIRKA ET AL SAFETY SWITCH MECHANI SM Filed March 2, 1928 2 Sheets-Sheet 2 F'IE'S an uc-nfou I r; J/RKH panel. will Patented Feb. 7,

SAFETY SWITCH MECHANISM Application filed March 2, 1928. Serial No. 258,482.

This invention relates to safety switch mechanism and is especially adapted for safety switches that are operated automatically by certain manual operations of parts that are adapted to be actuated for other functions without consideration of possible danger incurred, but which are positive in their action and certain to effect their safety function. The structure herein disclosed is adapted for use in the operation of many devices, such as panel boards, switch boards, etc., and is found particularly useful in automatically opening and closing electrical connections where currents of high amperage are employed. I

It is an object of our present invention to provide an automatic-safety switch that shall be operated by the manipulation of parts to wholly disconnect a fuse from the circuit for which it is adapted, and we haveshown for illustration in-this case, such switch operated by the swinging of the door of a panel box, though it is to be positively understood that we do not limit the application of the switch structure to panels or to parts operated by a door.

It is a further object of our invention to provide an automatic safety switch which shall embody detachable elements. of a circuit, one of which elements shall carry an elongated fuse bodily. so that when this element is moved'to break the circuit, the entire fuse will be disconnected at either end thereof. We shall illustrate the present switch mechanism embodying the advantages here referred to by mounting one or more fuses detachablv upon a swinging door of a panel box, so that opening the door will bodily disconnect the fuses from the circuit in the panels It is ahfurther object of our invention to provide an automatic safety switch which shall inclhde a movable member carrying detachable contacts thereon the removal of which frdm the main member, such as a break the circuit therein, it being a special provision of this structure that the contacts shall be mounted on an insulating block for vertical sliding movement on the saidmovable member, and that the action of ing circuits carrying currents. of

gravity, if such sliding movement is-in a vertical plane, will move the block with its contact out of registration with the corresponding contact of the stationary member, when the members are separated. We may therefore automatically break the circuit by the action of gravity.

With these and other objects in view, we have described our invented structure in the specification, recited the same in the appended claims, and illustrated the structure in the accompanying drawings, in Which Figure 1 is a side elevation of a panel box embodying our improvements;

Figure 2 is a perspective view of the same, showing the door open;

Figure 3 is a transverse section of the device taken in a plane indicated by the line 3-3 of Fig. 1;

Figure 4 is a vertical transverse section taken in a plane indicated by the line H of Fig. 1;

Figure 5 is a similar view showing the arts disconnected and certain of them moved out of registry, and

Figure 6 is a detail view partly in plan, a portion in transverse section, and certain parts broken away, of a covering for a contact clip. 1

Referring now to the drawings in detail, the numeral 10 designates a wall panel of a more or less conventional type having a rear chamber 11 for making suitable connections in electric circuits of various sorts, but here illustrated as intended for conductors formhigh amperage. L-bars 12 are designed to support a plate of insulating material 13 extending across the panel and for illustrative purposes said plate is shown as vertical and bearing on its front face a plurality of pairs of detachable contacts 14 of conducting material and which are here shown as clamps designed to receive conductor blades 15 carried by a swinging door 16 mounted upon the hinges 17 which are provided adjacent one of the edges of said door, the latter opening outward, and provided with a latch 18 of a very ordinary variety, and an operating handle 19 as shown in Fig. 1.

The hinged door 16 may be formed of a metal frame plate 20 bearing on its inner face spaced, gibs 21 which are detachably secured near the end margins of the plate 20 by bolts or screws, and having at one edge overlapping flanges 22 thereby providing a guide groove 23 for a purpose to be described. On the inner faceof the door plate 20, a metal plate 24 rectangular in form slides upon the door plate and parallel thereto with its edges guided in the said grooves 23. At the edge of the door nearest the hinge the guide member 21 is divided into portions 25 which are in alinement to serve the guiding function for the ed e of the metal plate 24 the same as the other ar or gib 21, but permitting between the separated portions, a swinging movement of an inwardly extending toe plate 26 which is welded to the sliding plate 24 at of the one edge and having an inwardly extending point 27 which is designed, when the door is closed, to be inserted in one of the notches 28 of a frame piece 29 adjacent the hinge side of the frame of the panel'lO. One of these notches will receive the point 27 when the plate 24. is in its normal position, as by reason of gravity, but under such conditions the uppermost notch will hold the point 27 if the plate 24 is moved upon the door plate manuall before the door is closed. 1

T e conductor blades 15 are mounted on metal bases 31 which bear on each, a clamp 30 adapted to receive therein the end of a fuse .32, which may be the conventional type of enclosed fuse, the base plates of a pair being separated for the approximate length fuse to be used. These base plates31 therefore, carry each a clamp 30 and a blade 15. spaced apart conveniently, and the several pairs of plates 31 are mounted upon the inner face of an insulating block 33 which in turn is bolted or otherwise fixedly secured to the inner surface of the plate 24, so that the sliding movement of the plate in the guides 21 serves to move the fuses carried by the clamps 30, as well as move the blades 15 into registry with the clamps 14 of the block 13, when the plate 24 is in the one position, or out of registry, when the block 33 is ermitted to slide to the other position.

11 the latter position, it is evident that the closing of the door 16 will place the blades 15, together with the fuses carried by the clamps 30, intermediate the pairs of clamps 14 and wholly out of contact with them. In the latter position, the toe 27 will not impede the closing movement because the latter may enter the notch 28.

The present invention is not especially concerned with the particular connections made in the chamber 11 between the several clamps 14, nor is it deemed of special interest in this case that there shall be a channel of any kind in one of the frame units. No claim is made herein to the structure of the clamps 14 provided with bolts 34 leading rearwardly through the plate 13 for conneetions of some sort. This construction has the special advantage of providing the contact pointsor clamps in pairs in'both frame members, so that separation of the frame members breaks the circuits or branches at two points in each line. This later condition enables the mounting of fuses detachably on one of the frame members and wholly disconnecting the fuse from thecircuit bodily when the frame members are separated.

The sliding metal plate 24 bears on its outer surface the warning signs on and off spaced vertically, so that as the plate 24 and its insulating block 33 is moved in the guides 21, the appropriate term will appear in the opening 35 in the plate 20. This provides for indicating the position of the fuses before the door is opened. Further provision is made for testing the condition of the connections in the interior of the mechanism by test openings 36 in the parts 20, 24 and 33, as shown in Fig. 1.

In many instances, it has been found desirable to provide coverings for contact clips, so that when the switch is open, such contacts are protected. In the instant case, the clips 14 remain in stationary position mounted upon the block 13, as shown in Figs. 3, 4 and 5. When the blades 15 are withdrawn from the clips 14, as by the opening of the door, the clips 14 will be seriously exposed over a very large surface, which is quite unsafe in use with circuits of high amperage.

We have shown in Fig. 6, a covering device intended to be used for protecting the external surface of a single clip, such as 14. In this view, numeral 37 designates the base plate of the clip 14, as a series of them is shown in Fig. 2. A hollow covering piece 38, shown here as of wood, but may be of other insulating material, fits neatly over the plate 37 and is provided with an outward hollow extension 39 which receives the separated arms of the clip 14, but has an opening 40 to permit insertion of the blades 15 longitudinally of said extension. One of these cover devices 38 is usually supplied for each of said exposed clips 14, and is provided with an end opening of the general cross outline of the clip, so that they cover may be moved over the clip into position thereabout and over the plate 37 and its attaching screw 34.

When the covers 38 are applied, a small screw 41 will be used to temporarily secure the cover in the position shown in Fig. 6. None of these covers is shown in the other views, but it is the intention of the inventors to use them on all the clips 14 that are mounted on the block 13. It is not consideredof material importance to protect the contacts upon the door because they are positively disconnected from the circuit when ever the door is opened.

0peratz'on.-Assuming that the desired circuits have been connected through the pair or pairs of clips 14, so that closing the break between the clips of the given pair will close the entire circuit, the fuses to be used are detachably mounted in the pairs of clips 30 to be entered in the circuit.. Further, as

suming that the door is open and the block 33 and plate 24 carrying the base plates 31 are in one extreme position in which the toe plate 26 may rest upon the one guide bar 25, the block 33 and its connected parts may be manually moved with one hand by pressing against one edge of the block until the point 27 will be in the plane of the notch 28, and the door 16lis closed by swinging the same by means of the handle 19 until the part 27 enters the notch. 28, when the latter may be relied upon to hold the fuse block 33 in one position while the door 16" is fully closed, the adjusting hand being removed as soon as entrance in the notch 28 is effected, after which, as the door closes, the blades 15 enter the corresponding clips 14 and the fuses are inserted in the circuits to complete the same.

While the door is closed, the circuit will fi remain complete unless a fuse is burned out. Testing by means of the openings 36 in the door may determine the condition of the fuses. The appearance of the sign reading in the opening 35 will indicate whether the block 33 and its fuses have moved in the guides. If it is desired to insert other fuses, the opening of the door will remove the toe point 27 from the notch 28 and the block 33 will, if it is in a vertical plane, automatically fall with its contacts and fuses and the blades therefor, so that if the door should be closed without any precaution as to safety, the blades 15 would not register with the clips 14 and the fuses would not be inserted in the circuit. During the replacement of new fuses the clips 30 carrying them will be wholly disconnected with any circuit in the stationary frame member 10 which in this case is shown as a panel. Sliding the insulating block 33 is essential to positioning the blades 15 in the plane required for contact with the clips 14 in the panel.

The lower notch 28, if the block is positioned vertically, is provided for the sole purpose of permitting closing the door when the fuses are not to be inserted in the cir- It has no other function. The upper notch 28 serves to hold the block in its raised position, and will release the same as soon as the toe 27 is withdrawn by the opening of the door. Not only is the action of our mechanism automatic by force of gravity, but the warning signs on the plate 24 others, and may in The protecting covers 38 may be applied to any or all of the clips 14. The mere removal of the attaching screw 41 permits the given cover to be removed laterally out of engagement with the clips and plate 37, so that it can then be wholly detached. These covers might, for example, be applied to the cli s 14 farthest from the hinge and not to t fact be used as a protective insulator for any conducting contacts, anywhere and for any purpose.

Any number of fuses may be detachably mounted on clips '30 on the same block 33, and the switch mechanism may be multiplied and arranged in series vertically or in other desired plane, in banks or in alinement on the same horizontal lane.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is 1.. In a safety switch, frame members movable toward and from each other, one said member bearing spaced contact points and the other member having a conductor carrying element slidably mounted thereon in a vertical plane,-the said conductor carrying element having spaced contact points normally out of register with the points on the rst-mentioned member when in its lower position by reason of gravity but in register therewith when in their raised position, and means connected to said contacts for receiving detachable fuses.

2. In a safety switch, frame members movable toward and from each other, one said member bearing spaced cont-act points and the other member having a conductor carrying element slidably mounted thereon in a vertical plane, the said conductor carrying element having spaced contact points normally out of register withthe points on the first-mentioned member when in its lower position by reason of gravity but in register therewith when in its raised position, and cooperating means on the two frame members to hold the conductor carrying element in its raised position when the frame members are in closed position.

3. In a safety switch, frame members movable toward and from each other, one said member bearing spaced contact points and the other member having a conductor carrying element slidably mounted thereon, the said conductor carrying element having spaced contact points normally out of register with the contacts in the first-mentioned member when in its extreme position of movement in one direction, but in register therewith when in its opposite position of movement thereon.

4. In a safety switch, a stationary frame member bearing spaced contact points and a frame member movable toward and from said member stationarymember, a conductor carrying element mounted slidably on said movable frame member and bearing contact points that register with the points on the stationary when in their extreme position of movement in one direction, but out of register therewith when in the opposite position of movement thereon, and cooperating means on the two frame members to hold the said conductor carrying element in its position in which the contact points are in registry, when the movable member is closed against the stationary member.

. 5. In a safety switch, frame members movable toward and from each other, one said member bearing spaced contact points and the other member having an insulating block slidably mounted thereon, a conductor member mounted on said insulating blockand being normally out of register with the contacts in the first-mentioned member when in its lower position, but in register therewith when in its raised position, and cooperating means on the two frame members to hold the insulating block and its conductor member in their raised position when the frame members are in closed position.

6. In a safety switch,a statlonary frame member bearing spaced contact points and a frame member movable toward and from said stationary member, an insulating block slidably mounted on said movable frame member and bearing spaced contact points, thatregister with the points on the stationary member when in their raised position, but normally out of register therewith when in the lower position by reason of the force of gravity, means connected to said contacts on said insulating block for receiving detachable fuse elements, and cooperating means on the two frame members to hold the insulating block in its raised position when the frame members are in closed position.

7. In a safety switch, a stationary frame member bearing spaced contact points and a frame member hinged upon said stationary member for swinging into open or closed position, an insulating block slidably mounted on said hinged member for slidable movement thereon and bearing spaced contact points that register with the points on the stationary member when in one position of movement, but out of register therewith when in the opposite position, means connected to said contacts on said block for receiving fuses detachably, and a toe plate secured to said block for movement therewith, there being a plurality of spaced notches positioned in said stationary member to receive said toe plate therein selectively.

8. Ina safety switch mechanism, a stationary frame member having spaced contact members, adoor member hinged to said frame for opening and closing movement thereon, spaced vertical gibs mounted adjacent the insulatingblock secured to the inner face of said metal plate for movement therewith, spaced contact members mounted on the face of said block, each contact member comprising a contact point for registering with said contact members on the stationary frame member in one position of movement of said block and a clip for receiving therein an end of a fuse detachably, and a toe plate secured to said metal plate and extending laterally therefrom for registry with portions of said stationary member, there being vertically spaced. notches positioned in said stationary member to receive said toe plate therein selectively.

9. In a safety switch mechanism, a stationary frame member'having spaced contact members, a door member hinged to said frame for opening and closing movement thereon, spaced vertical gibs mounted in parallelism each adjacent the lateral edges of said door member, said gibs having a lateral flange forming a guide slot extending the length of the gib, a metal plate mounted on the inner surface of the door member for sliding movement thereover with its lateral edges guided .in the saidslots of the gibs, an insulating block secured on the inner surface of said metaLplate, spaced contact members mounted on the face of said block, each contact member comprising a contact point registering with a contact member on the stationary frame member in one position of said block and a clip for receiving therein an end of a fuse detachably, and a toe plate secured to said metal plate and extending laterally therefrom for registry with portions of said stationary member; there being vertically spaced notches positioned in said stationary member to receive therein said toe plate selectively as the door member is closed.

10. In a safety switch, frame members movable toward and from each other, one said member bearing spaced contact points and the other member having a conductor carrying member slidably mounted thereon, the said conductor carrying member having spaced contact points out of register with the several points on the first mentioned member when in its extreme position of movement but in register therewith when in its opposite position, the first mentioned member and the conductor carrying member having a toe plate secured to one of them, there being spaced notches positioned in the other to receive the said toe plate therein selectively, when the said frame members approach each other.

11. In a safety switch mechanism, a stationary frame member having spaced contact members, a door member hinged to said frame for opening and closing movement thereon,

Y sition pf said block on the stationary frame member and door member having spaced contact 40 i membe spaced vertical gibs mounted adj acent the lat- .eral edges of and door member on the inner surface of the latter, a metal plate mounted on the inner surface of the door member for loose movement in said gibs, an insulat' faoeof said me plate for movement therewi spaced contact members mounted on the face of said each contact member on said block ering with one of the contact members on stationary member in one position ofsaid bloc and cooperatin means on the two the insulating block position when the frame members are in closed position. 12. In a safety switch mechanism, a stationary frame member having spaced contact rs, a door member hinged to said frame for opening and closing movement thereon, spaced vertical gibs mounted in parallelism each adjacent the lateral edges 0 said door member, said gibs having a lateral flange forming a guide slot extending the length of the gib, a metal plate mounted on the inner surface of the door member for sliding movement thereover with its lateral. edges ided in the said slots of th gibs, an msu atin ock secured on the inner surface of sai metal late, spaced contact members mounted on the face of said block, each contact member on said block registering with a contact member onthe stationa member in one poan cooperating means member to hold the insulating block in its raised position when the door member is closed 13. In a safety switch, a stationary frame points, and a me member hinged upon sa1d stationary member for swinging 1nt0 open or tionary member when the shdable element is position on the hinged membe out of register therewith when inthe opposite position on said hinged member. 7 v

In testimony whereof, we have hereunto guilscribed our names on the dates indicated e ow:-

On this must of February, a 1). 1928.

JOS. F. mum.

RKMOCURDY. 0 a mu fFb a fies n is .ayo emu-y RALPHnismsT. 

